Rayleigh waves are surface waves that can travel as ripples along or near the surface of the earth. During a seismic survey, seismic sources generate Rayleigh waves along with other types of waves. Classic reflection seismology typically ignores Rayleigh waves because these waves propagate horizontally, have limited depth sensitivity, and exhibit velocity dispersion. For onshore seismic exploration, much effort is concentrated on designing and deploying receiver arrays that can attenuate horizontally traveling surface waves. Moreover, classic seismic approaches for monitoring near surface regions typically require expensive data acquisition using a dense grid of seismic sources and receivers over a period of weeks to month(s). Due to the high cost of data acquisition, continuous or persistent monitoring of the subsurface over a longer period of time is considered unpractical.